New and ongoing transportation construction and improvement projects are likely to surpass $2 billion in the 10-county region next year.

Just three big projects account for more half of the spending: the light-rail extension to the North Shore, $435 million; the next, 8.5-mile-long section of the Mon-Fayette Expressway between Uniontown and Brownsville, $455 million; and a new Pennsylvania Turnpike bridge over the Allegheny River, $190 million.

But plenty of traffic disruptions will be felt almost everywhere starting Jan. 3 when PennDOT closes the Boulevard of Allies east of the Birmingham Bridge, affecting the gateway to Oakland for 11 months.

Work will continue to ramp up in southwestern Pennsylvania through March, when another high-profile project -- the continuing Parkway East/I-376 rehabilitation -- will move to the suburbs, extending from the Edgewood-Swissvale Interchange to Business Route 22 in Wilkins.

All 7.5 miles of the Parkway East will be closed outbound over three weekends and inbound over two weekends. Lanes on the region's second busiest highway will be closed or restricted at other times through November, as they were this year for work east of Bates.

The amount to be spent by PennDOT in the District 11 counties of Allegheny, Beaver and Lawrence next year will be about $250 million, substantially less than the $300 million paid to contractors for work performed in the now-ending construction season, despite new transportation funding legislation passed last summer.

Most of it will be spent locally to start correcting a backlog of slide conditions and repairing structurally deficient bridges.

Statewide, PennDOT expects to award about $2 billion in new road and bridge contracts, or about $200 million more than the current year.

Some of the other major transportation projects on next year's calendar in Allegheny County include:

• North Shore Connector -- The Port Authority will begin testing its new tunnel-boring machine next month and dig the first of two twin tunnels under the Allegheny River shortly thereafter.

• I-279/Parkway North -- Lanes will be closed and restricted on weekends and overnight hours while concrete slabs are repaired between the Fort Duquesne Bridge and Camp Horne Road in the North Hill. Works starts in the spring.

• I-79 -- The $63 million rehabilitation of 6.5 miles between the Ohio River and the I-279 junction in Franklin Park will resume for a second year, this time funneling traffic into the northbound side while the southbound lanes are rebuilt from the ground up.

• I-79/Parkway West -- Work continues on building the two "missing ramps" at the massive interchange and widening 1¹/₂ miles of the parkway in Collier and Robinson.

• Liberty Tunnels -- Extensive concrete, conduit, lighting and facade repairs are to start by summer and last more than a year. Tunnels will be closed in off-peak hours.

• Route 88 -- When the current rebuilding ends between McNeilly Road and Sixth Street/Killarney Drive in Castle Shannon, PennDOT will add turning lanes, install new signals and repave 0.6-mile of old Library Road/Route 88 south of there.

• West End Circle -- Realignment, reconstruction and bridge replacement work that began last fall will pick up this year and continue for at least two more years.

• Route 28 -- Widening, resurfacing and replacement of 17 bridge decks continues through parts of Springdale, Harmar, Frazer and East Deer, shifting and restricting traffic. Also, stabilization work, fence installation will take place in slide-prone area south of RIDC Park.

• East Ohio Street -- New ramp should be finished by mid-year, enabling Route 28 south traffic to proceed nonstop to I-279 rather than negotiating traffic signals and congesting the city street.

• Warrendale-Bayne Road -- PennDOT is spending $5 million to widen the road to four lanes and add turning lanes on 1.5 miles of Route 19 in Marshall.

• I-579/Crosstown Boulevard -- Pavement repairs and resurfacing will take place below Mellon Arena while traffic volumes are lower due to Boulevard of Allies construction near Oakland.

• Business Route 22 -- Milling, resurfacing and signal upgrades will be made between the Parkway East and Route 48 intersection, a nearly 8-mile project through the heart of the Monroeville business district.

• Penn Circle -- Concrete will be repaired and the Penn Circle area paved to Fifth Avenue, Point Breeze Court and Frankstown Avenue.

• Boulevard of Allies -- PennDOT plans to resurface 2.8 miles inbound starting around the Birmingham Bridge;

• Westinghouse Bridge -- More than $2 million in repairs are planned on the landmark concrete arch span carrying Route 30 between East Pittsburgh and North Versailles.

• Route 910 -- The bridge over I-79 will be replaced, a half-width at a time in order to maintain traffic, as part of improvements and painting on four bridges crossing the interstate in Marshall and Franklin Park.

• Rankin Bridge -- Allegheny County Public Works Department will rehabilitate the 56-year-old Mon River bridge and widen the deck starting in May. One lane of traffic will be maintained each way during construction on the popular route to Kennywood and the Waterfront in Homestead.

• East Carson Street -- The city plans to rebuild and widen East Carson between 25th and 33rd streets, past the SouthSide Works development.

Some of the other major transportation projects on next year's calendar for the Pennsylvania Turnpike include:

• Mileposts 2-10 -- A $102 million reconstruction to widen the toll road to three lanes in each direction continues for a second year.

• Allegheny Valley Interchange -- Work will move from building piers to building a cast-in-place deck for the new $190 million Allegheny River Bridge and new roadway approaches in proximity to the Route 28 interchange.

• Mileposts 68-75 -- In the fall, the turnpike will accept bids for a $20 million to $30 million conversion of the Seanor Church Road underpass in Hempfield into an overpass, and do extensive excavation to straighten curves in preparation for a $120 million mainline widening between the Irwin and New Stanton interchanges, starting in 2009. Also, the turnpike recently awarded contracts to replace the Route 136 and Glen Fox Road bridges over the toll road.

Some of the other major transportation projects on next year's calendar elsewhere include:

• Point Marion Bridge -- PennDOT broke ground this month for a new $21 million bridge to carry Route 88 over the Monongahela River between Fayette and Greene counties.

• Racetrack Road/I-79 -- Two troublesome intersections just off the interstate in Washington County are being realigned into a single, four-way intersection, and turning lanes are being added to Pike Street and Allison Hollow Road at a cost of $3.4 million.

• Route 22, Washington County -- Several miles will be patched and paved starting at the West Virginia line.

• Route 22, Westmoreland County -- The last two contracts will be under way to widen and upgrade the rest of the highway from Route 22 east to the Indiana County line. Meanwhile, work will finish up on other sections from Murrysville to Delmont and from Route 981 to Route 982 in Derry Township.

• Route 366 -- Single lane traffic will be maintained, one way at a time, while the existing bridge between Plum and Lower Burrell is widened and highway approaches are modified.

• Parnassus Triangle Phase 2 is to begin this fall in New Kensington, consisting of widening Stevenson Boulevard to four lanes between Bridge and Seventh streets, upgrading traffic signals and replacing a structure spanning Little Pucketa Creek.

• Route 119, Fayette County -- Resurfacing and other improvements are to begin in late spring in Bullskin, Connellsville Borough and Connellsville Township.

• East McMurray Road, Peters -- The road widening will add left turn lanes at South Center Church Road and North Center Search Road, with a new traffic signal at South Center.

• Turtle Creek Bridge -- The bridge replacement project extends from the Duff Park entrance north to a point just south of the railroad crossing.